TECHNICAL FIELD
The present application relates generally to gas turbine engines and more particularly relates to a filter washing system for use with a gas turbine air inlet and the like.
BACKGROUND OF THE INVENTION
Air entering a turbine compressor inlet and similar devices should be filtered before compression or other use. Impure inlet air laden with dirt, debris, dust particles, salt, and other contaminants may damage the compressor blades, plug cooling passages, and damage other types of power generation equipment via corrosion, erosion, fouling, and the like. Such damage may reduce the life expectancy and the overall performance of the generation equipment. To avoid this problem, the inlet air may pass through one or more filters to remove the contaminants.
The air filters, however, may have a relatively short life span due to accumulation of the dirt, debris, and other types of contaminants. This accumulation also may raise the pressure drop across the filter element. Raising the pressure drop reduces the overall power output and the efficiency of the gas turbine engine. As such, the filter elements typically may be replaced when the pressure drop reaches the point in which the gas turbine operator deems the loss of machine efficiency exceeds the costs of the replacing the filters. Many gas turbine engines may have automatic controls that signal when the filters have reach a predetermined set point and that filter replacement is needed. If the operator does not replace the filters at the alarm point, additional controls may shut the gas turbine engine down to prevent inlet or filter implosion due to high filter element pressure drops. The gas turbine engine typically may be shutdown for the replacement of the filters.
Frequent filter replacement thus may result in high maintenance costs to the gas turbine end user in terms of labor and filters as well as the loss of revenue due to engine downtime and unavailability. Likewise, online replacement of the filters may result in premature wear of the gas turbine internal components.
To date, known self-cleaning inlet air filter elements have relied on a reverse blast of compressed air that creates a shock wave which knocks off the accumulated dirt, debris, and other contaminants off of the filter elements. The dirt and debris located at the top of the filter elements, however, may accumulate and may not be effectively cleaned by the compressed air self cleaning.
There is thus a desire for an improved inlet air filtering systems. Such systems preferably can avoid the accumulation of dirt, debris, and other contaminants without an increased pressure drop therethrough. Overall system efficiency and performance also should be improved.
SUMMARY OF THE INVENTION
The present application thus provides for a filter system for an air inlet of a gas turbine engine. The filter system may include a number of filters positioned about the air inlet and a water spray system positioned to spray the filters. The filters may include a hydrophobic or an oleophobic filter media therein.
The present application further provides for a filter system for an air inlet of a compressor of a gas turbine engine. The filter system may include a number of filters positioned about the air inlet of the compressor and a number of spray nozzles positioned about the filters to spray the filters with water. The filters may include a hydrophobic or an oleophobic filter media therein.
These and other features of the present application will become apparent to one of ordinary skill in the art upon review of the following detailed description when taken in conjunction with the several drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a gas turbine engine.
FIG. 2 is a schematic view of an inlet filter system as is described herein.
FIG. 3 is a schematic view of an alternative embodiment of the inlet air filter system as is described herein.
FIG. 4 is a schematic view of an alternative embodiment of the inlet air filter system as is described herein.
DETAILED DESCRIPTION
Referring now to the drawings, in which like numbers refer to like elements throughout the several views,
FIG. 1 shows a schematic view of a
gas turbine engine 10. As is known, the
gas turbine engine 10 may include a
compressor 20 to compress an incoming flow of air. The
compressor 20 delivers the compressed flow of air to a
combustor 30. The
combustor 30 mixes the compressed flow of air with a compressed flow of fuel and ignites the mixture. (Although only a
single combustor 30 is shown, the
gas turbine engine 10 may include any number of combustors
30). The hot combustion gases are in turn delivered to a
turbine 40. The hot combustion gases drive the
turbine 40 so as to produce mechanical work. The mechanical work produced in the
turbine 40 drives the
compressor 20 and an
external load 50 such as an electrical generator and the like. The
gas turbine engine 10 may use natural gas, various types of syngas, and other types of fuels. The
gas turbine engine 10 may have other configurations and may use other types of components. Multiple
gas turbine engines 10, other types of turbines, and other types of power generation equipment may be used herein together.
FIG. 2 shows a schematic view of an inlet
air filter system 100 as is described herein. The inlet
air filter system 100 may be positioned about an
inlet 110 of the
compressor 20 or other type of air inlet system.
The inlet
air filter system 100 may include a number of
filters 120. The
filters 120 may include a hydrophobic (“water-fearing”) and/or an oleophobic (“oil-fearing”)
filter media 130 therein. The hydrophobic and/or the
oleophobic filter media 130 may include a base media, a membrane, or another type of coating and/or combinations thereof. The
filter media 130 may be a web of synthetic fibers. The
filter media 130 may be made out of PFTE (Polytetrafluoroethylene), ePFTE (Expanded Polytetrafluoroethylene), and similar types of materials. Examples of
filters 120 with a hydrophobic and/or a
oleophobic filter media 130 include a F9MH filter sold by General Electric Company of Schenectady, New York, a Duravee HXL 98 Filter sold by AAF International of Louisville, Kentucky, and a D-Salt filter sold by Donaldson Company, Inc. of Minneapolis, Minn., and similar types of
filters 120 and hydrophobic or
oleophobic filter media 130.
In this example, the
filters 120 may be in the form of a
grid 140. Each of the
filters 120 may be inclined forward to promote drainage. The
filters 120 may be
static filter elements 150. The
filters 120 may be pleated or non-pleated. The
filters 120 may include a frame on one or both sides of the
filter media 130. The frame may be configured to seal about a permanent structure within the overall filter house or otherwise positioned.
The inlet
air filter system 100 also may include a
water spray system 160. The
water spray system 160 may include a
water tank 170. The
water tank 170 may have a volume of
water 180 therein. The
water 180 may be at ambient temperature or the
water 180 may be chilled. The
water tank 170 may be in communication with any number of
spray nozzles 190. The
spray nozzles 190 may be located upstream and/or above the
filters 120. Other positions may be used herein. Any number of
spray nozzles 190 may be used.
In use, the
filters 120 of the inlet
air filter system 100 may keep dirt, debris, and other types of contaminants from the
inlet 110 of the
compressor 20. The
filters 120 accumulate the dirt, debris, and other contaminants thereon. The inlet
air filter system 100 also may use the
water spray system 160 to clean the
filters 120. Specifically, the
filters 120 with the hydrophobic or
oleophobic filter media 130 may be self cleaned via the
water 180 from the
spray nozzles 190. The water spray will remove the accumulated dirt, debris, and other contaminants from the
filters 120 while the use of the hydrophobic or
oleophobic filter media 130 prevents the water with the dirt, debris, and other contaminants from passing therethrough.
Use of the inlet
air filter system 100 with the
water spray system 160 also may have the further benefit of providing power augmentation to the
gas turbine engine 10. Specifically, the
water 180 may cool an
inlet air stream 185 via evaporative cooling from the
water spray system 160, in which case cooling may be via evaporative cooling and/or chilling. Likewise, the
water 180 may be chilled when used with the
water spray system 160. When providing power augmentation, the spray of
water 180 may be substantially continuous such that the cleaning may be continuous and may provide a more thorough cleaning.
The use of the hydrophobic or the
oleophobic filter media 130 allows the sequence of equipment (the
filters 120 and the water spray system
160) to be reversed from what has been traditionally provided. Because the
water spray system 160 is now upstream of a hydrophobic or an oleophobic
membrane filter material 130, pure water does not have to be used therein. Rather, the
oleophobic filter material 130 allows for a broader range of impurities due to the nature of the
filter material 130 in preventing lower surface tension solutions from passing therethough.
The inlet
air filter system 100 thus may increase the life of the
filters 120 by removing accumulated dirt, debris, and contaminants therefrom. The inlet
air filter system 100 also may prevent a decrease in the overall output of the
gas turbine engine 10 by keeping the
filters 120 clean of dirt, debris, and contaminants so as to keep the inlet pressure drop relatively low. The inlet
air filter system 100 also may provide power augmentation to the overall
gas turbine engine 10 by cooling the
inlet air stream 185 by providing either evaporative cooling or chilling. Overall maintenance costs may be decreased by increasing the life of the
filter 120. Likewise, the availability of the
gas turbine engine 10 may be increased by increasing the life of the
filters 120. The inlet
air filter system 100 is easily retrofitable in existing
gas turbine engines 10. By avoiding the known compressed air reverse flow self-cleaning filters described above, the inlet air filter system also has an acoustical benefit over these known systems.
The inlet
air filter system 100 may have many different geometries. For example,
FIG. 3 shows an alterative embodiment of an inlet
air filter system 200. The inlet
air filter system 200 also may include a number of
filters 210 with a hydrophobic or an
oleophobic filter media 220 therein. In this embodiment, the
filters 210 may take the form of canister type filters
230 in a
cross flow arrangement 235. These canister filters
210 may be pulse self-cleaning
filters 240 or static filters. As opposed to the
static filter elements 150, the pulsed self-cleaning
filter elements 240 may use a pulse of air to aid in cleaning the
filters 210 as described above. A canister-type filter is available from Donaldson Company, Inc. of Minneapolis, Minn. and sold under the mark “GDX” or “GDS”. Similar configurations maybe used herein.
Likewise,
FIG. 4 shows a further embodiment of an air
inlet filter system 300. The inlet air filter system also uses a number of
filters 310 with a hydrophobic or an
oleophobic filter media 320 therein. These
filters 310 also may be in the form of a
canister 330. In this embodiment, the filters may have an up
flow position 340. Similar configurations may be used herein.
It should be apparent that the foregoing relates only to certain embodiments of the present application and that numerous changes and modifications may be made herein by one of ordinary skill in the art without departing from the general spirit and scope of the invention as defined by the following claims and the equivalents thereof.